The long-term objective of this project is to update, enhance, and then commercially distribute two computer programs which implement the unique multivariate analysis techniques developed by the psychologist Robert Tryon with NIMH support during the 1960s. One main goal is to produce an enhanced Fortran 77 version of the main Tryon system (TRYSYS), portable across all mainframe computers. A second main goal is to refine and greatly expand a new Fortran program (TRYCLUS) specifically designed for maximum portability and enhanced user-friendliness. Tryon multivariate analysis techniques are especially useful for the following biomedical research tasks: analysis of the dimensionality of assessment inventories; construction of reliable assessment scales from large item pools; comparison of factor structures across diverse clinical groups; development of clinical taxonomies, produced by clustering cases in a multidimensional space defined by reliable assessment scales; and Monte Carlo prediction of important outcome or criterion variables from taxonomic group membership. TRYSYS work will focus on systematically updating the code so that it is written completely in Fortran 77 and is parameterized, for ease in adjusting the size of datasets permitted to the amount of computer memory available. TRYCLUS work will focus on adding to it additional data processing and statistical analysis techniques and further enhancing its user-friendliness, especially in the microcomputer (PC) environment.